The Journal of
Organic Chemistry VOLUME55, NUMBER 16
AUGUST3,1990
0 Copyright 1990 by the American Chemical Society
Communtcattons An Unusual Base-Mediated Cyclization of Ketimines Derived from 2-(Trifluoromethy1)aniline That Involves the Trifluoromethyl Group: An Expedient Route to 2-Arylquinolines Lucjan Strekowski,*J' Roman L. Wydra,la Marek T. Cegla,la Agnieszka Czarny,la Donald B. Harden,la Steven E. Patterson,la Merle A. Battiste,lb and James M. CoxonlC Departments of Chemistry, Georgia State University, Atlanta, Georgia 30303, University of Florida, Gainesville, Florida 32601, and University of Canterbury, Christchurch 4, New Zealand
Received May 7, 1990
Summary: 6-(Substituted methylene)-N-(arylalkylidene)-2,4cyclohexadien-l-imines, such as 13,17,and 21 (Scheme 11) are suggested intermediates in a novel synthetic route to 2-arylquinolines based on the reaction of trifluoromethyl-substitutedketimines, such as la,with strong bases. The chemistry of organic fluorine compounds is dominated by nucleophilic aromatic substitution and by numerous classical transformations in which fluorine-containing groups are stable substituents.2 By contrast, examples of a nucleophilic substitution of the trifluoromethyl group and formal nucleophilic displacement of the fluorines of this group, which do not involve a direct nucleophilic attack, are rare.t4 In this paper we describe a facile route to substituted quinolines via anionic cyclization of aralkylketimines la (Scheme I) and 9 (eq 1) derived from 2-(trifluoromethy1)aniline in which each fluorine of the CF3 group is (1) (a) Georgia State University. (b) University of Florida. (c) University of Canterbury. (2) See,for example: (a) Hewitt, C. D.; Silvester, M. J. Aldrichim. Acta 1988, 21, 3. (b)Fluorine-Containing Molecules: Structure, Reactiuity, Synthesis and Applications; Liebman, J. F., Greenberg, A., Dolbier, W. R., Jr., EMS.;VCH Publishers, Inc.: New York, 1988. (c) Chambers, R. D.; Sargent, C. R. In Aduances in Heterocyclic Chemistry; Katritzh. A. R.. Boulton. A. J.. Eds.: Academic: New York. 1981: Vol. 28, Chapter 1. id) Hudlicky, M. Chemistry of Organic Fluorine Compounds: Ellis-Horwood: Chichester, 1976. (3) For a review, see: Kobayaehi, Y.; Kumadaki, I. Ace. Chem. Res. 1978, 11, 197. (4) (a) Elsheimer, S.; Slattery, D. K.; Michael, M.; Weeks, J.; Topoleski, K. J. Org. Chem. 1989,54,3992. (b) Elsheimer, S.;Michael, M.; Landavam, A.; Slattery, D. K.; Weeks, J. J. Org. Chem. 1988,53,6151. (c) Taylor, S.L.; Martin, J. C. J . O g . Chem. 1987,52, 4147.
0022-3263/90/1955-4777$02.50/0
.q-$Q-&+d Scheme I
Ph
N
